Self-locking bolt



Get. 31, 1944. H. NA IN- 2,361,491

SELF LOCKING BOLT Filed May 27, 1942 15 17 l6 is 20 INVENTOR Mam MW ATTORNEYS Patented Oct. 31, 1944 UNITED, STA'lE1S,,A'FENT oFrlcE SELF-LOCKING BOLT Harold'Nagin, Pittsburgh, Pa, assignor to Reliance Steel Productsflompany, McKeesport, Pa., a corporation of Pennsylvania Application May '27, 1942, Serial No. 444,681 11 Claims. (ol. 85-5) My invention relates in general to a bolt and particularly to a self-locking bolt or pin which has a head on one end and means on the other end which normally serves to restrain the bolt against accidental endwise movement, such means being of the type which can be readily operated. to permit endwise movement of the bolt.

Such bolt may be very readily placed in posi tion to unite members such as portions of a knockdown bridge or other temporary or de mountable structure.

Heretofore bolts of this type have employed relatively expensive detent means and are frequently of somewhat intricate designs. My invention consists of an improvement in such bolts or pins and provides a device which will be positively retained in position and can be quickly and easily inserted or removed by the operation of a spring actuated locking member. A bolt in cluding the detent means of my invention is simple in construction, relatively inexpensive to manufacture, sturdy and simply operated. I

In the accompanying drawing I have shown for purposes of illustration several preferred em-' bodim'ents of my invention.

Fig. 1 is a fragmentary View of the body of the bolt, 1

Fig. 2 is a fragmentary view in section and to larger scale ofthe end of the bolt showing the detent in elevation,

' Fig. 3 is a View partly in side elevation and partly in section of a modified bolt,

Fig. 4 is a view in elevation of the top of the bolt .shown in Fig. 3,

Fig. 5 is aview of a modified detail and Fig. 6 is a view showing the bolt in side elevation securing three members in assembled position.

In Figs. 1 and 2 of the drawing, the numeral lll indicates a bolt made according'to my invention. The bolt ll] consists of a shank portion ll, a head l2 which may be formed integral with the shank, or separately made and threaded on the end of the shank, and a point portion [3, in or adjacent to which the locking mechanism is located.

The detent M is preferably circular in section and has the upper end, as viewed in Fig. 2, cut away on a slope l5 of the order of 45. A V- shaped groove I6, having plane shaped sides or cam faces I1 and I 8, is formed in the body of the detent and on the same side as the slope IS. The inclination of the upper cam facell with the vertical is less than the inclination of the position as shown in Fig. 2.

lower cam face [8 with the vertical. Suitable angles are-30 and 55 respectively. Thedetent M is slidably received in theround aperture or hole IS in the shank ll adjacent the pointed end l3.

A circular passage or bore 2'. extends from the.

point of the bolt rearwardly along the :bolt axis and opens into the aperture Ill. In this passage a conical pointed cylindrical pin 2-! is slidably received and is urged along the passage withv the pointed end extending toward aperture ill.

by a coiled spring 22, one end of which bears against the unpointed end of the pin, and the. I other end against a screw 23 which is threaded into the outer end of the passage 28. The sides of the cone point form anJang'le of about The detent M is slightly less in length than the diameter of the shank, and the ends are curved so that the detent when forced into the hole l9 does not protrude, and the bolt can thus.

freely slide through a hole which is of the same diameter as the shank portion H. The roove i6 is so located that when the pointed end of pin 2! is at the bottom of the groove-the upper.

or sloped end of the detent will project above the shank H of the boltto the coupling or flocking.

spring 22 acting through the cooperation of the pointed :end of pin 2=l and the cam face ll urges the detent upwardly and holds it in looking po sition. When it is desired to move the bolt endwise the detent M is pushed into the hole 19 by pressure exerted on the sloped face l5, where-'" upon the bolt may be moved errdwise. As soon r as the downward pressure on the detent is re leased the force-of thespring '22 acting on the pin 2| and cooperating cam face ll will move the detent outwardly to locking position as shownin Fig. 2.

In Figs. 3 and 4 I have shown a modified formof my invention, I-Iere the detent 2 5, preferably circular in cross section, is slidably received in the hole 25 which does not extend all the Way through the shank 26. The detent has a sloped face 27 for-med on the upper or outer 'end' and on the opposites'ide a portion is cut away to form a shoulder 28. The lower part of the detent has a cam face 29 formed on the side opposite the shoulder 28. The cam face is preferably at a 45 angle, and cooperates with a like cam face '30 on the end of pin'iil which is slidably received in the axial bore 32. The pin 3| is urged toward,

the hole 25 by the compressed coil spring 33 which bears at its outer end against the screw 34'-threadedly secured in the outer end or the The force of the" bore 32. The movement of the pin 3| toward the detent 24 urges the detent upwardly to looking position. The outward or upward movement of the detent 24 is limited by the shoulder 28 bearing against a stop plate 35 which is set into the shank II and attached thereto by the screw 36. The top of the plate 35 is curved to correspond with the shank 26 and does not extend thereabove. The stop plate .35also insures that the detent 24 will not turn in the hole 25. The detent or catch 24 is of such length and the shoulder so located that in the locking position, I

see Fig. 3, the outer end of the detent will ex-' tend beyond the shank and when forced into the hole 25 it will be received in the hole 25 so that the outer end of the catch will be below the surface of the shank a position which will be referred to as the releasing position.

In Fig. 5, I have shown a modified pin am for use in place of pin 3| in the bolt shown in Figs. 3 and 4. The point 31 of the pin is conical.

In Fig. 6, I have shown a bolt similar tothe bolt shown in Figs. 3 and 4 in coupling position, where it serves to secure together the members A, B and C which may be parts of a bridge or any other structure which it isv desired to releasably,

couple together. i

An important feature of my invention resides in the fact that the boltmay be prepared to receive the detent by two simple drilling operations, one at right angles tothe axis of the bolt and the other along the axis. The remaining parts, save the spring, are simple and inexpensive screw machine products.

The point portion of the bolt is tapered to provide for easy insertion of the bolt into the openings in the members to bev coupled. The

bolt is customarily made of metal although other materials such as plastic could be employed for all or some of the parts except the spring for urging the pin into or against the detent.

It will be evident from the foregoing that I have invented a simple, inexpensive and positive self-locking bolt or coupling "pin which can be used to secure various membersof a structure together. The bolt can be easily inserted in coupling position and locked against accidental displacement, and when desired the bolt can be quickly and readily unlocked (by manual actuation of the detent) and then withdrawn from the coupling position,

While I have illustrated and described certain preferred embodiments of my invention, it will be understood that this is merely by way of illustration and that the invention may be embodied and practiced in constructions other than those specifically disclosed herein.

I claim as my invention:

1. A self-locking bolt including .a head, a shank, and a point portion, an aperture in the shank adjacent the point portion, a detent slidably received in the aperture, said detent having a V-shaped groovein the side thereof, a passage extending from the end of the point portion into the aperture, a pin in said passage, and means for urging the pin toward said aperture into engagement with said detent.

2. .A self-locking bolt including a head, a shank, and a point portioh, an aperture in the shank adjacent the point portion, a detent slidably received'in the aperture, said detent having a V-shaped groove in the side thereof, a passage extending from the end of the point portion into the aperture, a pin in said passage, means forclosing the outer end of the passage, an d a spring the aperture, 2. pin in said passage, and means for urging the pin toward said aperture into engagement with said detent.

4. A self-locking bolt including a head, a

shank, and a point portion, an aperture in the shank adjacent the point portion, a detent slidably received in the aperture, said detent having a V -shaped groove in the side thereof, the sides of the groove being plane surfaces, the upper side being at an angle to the vertical which is smaller than the angle of the lower side, a passage extending from the end of the point portion into the aperture, a pin in said passage, and means for urging the pin toward said aperture into engagement with said detent.

5. In a self-locking bolt including a head, a shank, a point portion and a depressible detent in the shank adjacent the point portion, the invention'which consists of detent means all parts of which are slidably received in a hole of constant section in said shank substantially at right angles to the longitudinal axis of the shank, said detent being less in length than the depth of the hole, a cam surface on said detent angularly disposed with respect to the vertical axis of the detent, a passage extending from the hole to the point portion and longitudinally of the bolt, a pin of uniform section in said passage. a cam element on said pin, and means inside the passage for urging the cam element of the pin against the cam surface of the detent.

6. In a self-locking bolt including a head, a

in the shank adjacent the point portion, the invention which consists of detent means all parts of which are slidably received in a hole of constant section in said shank substantially at right angles to the longitudinal axis of the shank, said detent being less in length than the depth of the hole, a cam surface on said detent angularly disposed with respect to the vertical axis of the detent, a passage extending from the hole to the point portion and longitudinally of the bolt, a pin of uniform section in said passage, a cam surface on said pin, and means inside the passage for urging the cam surface of the pin against the cam surface of the detent, and means for restraining the outward movement of the detent.

7. In a self-locking bolt including a head, a shank, a point portion and a depressible detent in the shank adjacent the point portion the invention which includes detent means all parts of which are slidably received-in a hole in said shank substantially at right angles to the longitudinal axis of the shank, said detent being less in length than the depth of the hole, a cam surface on said detent angularly disposed with respect to the vertical axis of the detent, a passage extending from'the hole to the point portion and longitudinally of the bolt, a closure for said passage, a pin of uniform section in said passage, a cam surface on said pin, and means inside the passage. between the pin and the closure forurging the cam surface of the pin against the cam surface of the detent, and means for restraining the out:

ward movement of and angular movement of the detent.

8. In a self-locking bolt including a head, a shank, a point portion and a depressible detent in the shank adjacent the point portion, the in vention which comprises detent means all parts of which are slidably received in a hole in said shank substantially at right angles to the longitudinal axis of the shank, said detent being less in length than the depth of the hole, a cam surfaceon said detent angularly disposed with re;- spect to the vertical axis of the detent, a passage extending from the hole to the point and longitudinally of the bolt, a pin of uniform section in said passage, a cam surface on said pin', a

spring inside said passage bearing against {the pin and means located at the point portion end of tha passage for adjusting the tension of said spring.

9. In a self-locking bolt including a head, a shank, a point portion and a depressible detentin the shank adjacent the point portion, the invention which comprises detent means all parts of which are slidably received in a hole in said shank substantially at right angles to the longitudinal axis of the shank, said detent being less in length than the depth of the hole and movable from a locking to a releasing position, a cam surface on said detent angularly disposed with respect to the vertical axis of the detent, a passage starting from the hole and extending to the point of the bolt, a pin of uniform section in said passage, a cam surface on said pin, a spring inside said passage bearing against the pin, said cam surfaces being so disposed that movement of the pin away from the point moves the detent toward the locking position and a threaded member closing the outside of the passage and confining one end of the spring.

10. A selflockin'g bolt, including a head, a shank portion, and a point portion, the shank portion having a hole of uniform section extending'substantially therethrough, and transverse to the longitudinal axis of the bolt, the bolt having a passage extending from the point portion and terminating in the hole, a detent all portions of which are movable-in and out of said hole, a pin of substantially uniform section within the passage and movable therealong, a closure for the outer end of the passage, means between the closure and the pin ffori'urging'the pin along the passage, a cam surface on the detent, a cam surface on the inner; end of the pin, said cam surfaces being so disposed that movement of the pin away from the point portion of the bolt moves the detent toward the locking position.

11. A self-lockingbolt including a head, a shank, and a point portion, an aperture in the shank adjacent the point portion, a detent slidably received in the aperture, said detent having a surface receding from the side of the detent and at an angle thereto, a passage extending from the end of the point portion into the aperture, a pin in said passage and means for urging the pin toward said aperture and in contact with said surface.

HAROLD NAGIN. 

